There is.
What you refer as "dropdown" is called the ItemActionPanel which calls ItemActions.
You can set it up in any ItemViewSlotContainers including the ItemShapeGrid. But it is optional, that's why it is not setup by default.
Check out this video it shows how to setp the item actions for an InventoryGrid, but it works the same way for the ItemShapeGrid (within the UIDesigner panel for the ItemShapeGrid)